The exemplary embodiments of the present invention generally relate to knobs. More particularly, the exemplary embodiments relate to reducing knob wobble when the knob is operated.
Generally, mechanical valves are used to control the flow of gas in, for example, a gas operated appliance such as a cooktop. Stems coming out of the valves are rotated to control the onset of flow as well as the flow rate. Generally, while the valve body is hidden from view, the stem will extend through openings in a surface of the appliance so that a control knob can be affixed to the stem. The length of the stem and the construction of the valve often lead to an undesirable level of lateral wobble or play in the control knob.
Gas appliance control knobs are generally loose feeling when compared to for example, electrical appliance or electronic control knobs. The looseness of the gas appliance control knobs may be due to the nature of the gas valve and stem assembly and to the fairly large distances between the consumer interface point on the control knob and the valve body. For example, the stem extending from a gas valve may generally have anywhere from 0.5 to 2.0 degrees of angular play (See FIGS. 1A and 1B). In some applications the distance between the control knob and the valve body can be over 2 inches. This combination of stem length and angular play can lead to lateral movement of the control knob of about three tenths of an inch during operation of the control knob. As a comparison, control knobs for other appliances such as radios and receivers have a play of about two to three hundredths of an inch.